The present invention relates to electric motors, and more particularly to electric motor housings.
An electric motor commonly includes a housing which encloses a shaft, a rotor, a stator, and electrical components utilized to operate the motor. For motor operation, the electrical components are electrically coupled to an electrical conduit. The housing commonly includes an access aperture which provides access to the electrical components for such purposes. A cover plate closes the access aperture when the motor is in use. The cover plate is a flat metal plate.
The electrical conduit may include either (a) a power cord that removably couples the motor to a power source, or (b) a line lead that permanently couples the motor to a power source. The electrical conduit generally travels through an aperture or opening formed in the housing. The housing may include both a power cord aperture for use with a power cord, and a line lead aperture for use with a line lead. It is known to have a power cord pass through the above-mentioned access aperture. In this case, the access aperture includes a rectangular notch or cut-out which defines an opening with a flat metal plate cover plate when the cover plate closes the access aperture. The power cord passes through this opening. A grommet can be placed in the notch, around the cord, for sealing.
When a housing includes two apertures, it is desirable to seal the unused aperture so contaminants (e.g., water, dirt, debris, etc.) do not enter the housing and interfere with motor operation. A properly sized plug is often inserted into the unused aperture to provide such a seal. Thus, when the motor is used without a cord passing through the opening defined in the access aperture, a plug must be placed in the notch to seal the housing. A problem with this approach is that the plug may be removed and/or fall out (e.g., the plug may fall out when a portion of the housing is removed for maintenance purposes). When the plug is not reinserted as previously installed, the motor is susceptible to contaminants.
Accordingly, the invention provides a motor that substantially alleviates the above-described and other problems with existing housings. The motor includes a cover plate that covers the access aperture and that is attachable to the housing in a first orientation that leaves an opening for a power cord, and in a second orientation that seals the aperture from contaminants without the use of a plug.
In the preferred embodiment of the invention, the cover plate has a semi-cylindrical protrusion forming a complementary recess, and the motor housing has therein a semi-cylindrical recess adjacent the access aperture. In the first orientation, the coverplate is mounted on the housing such that the cover plate recess faces the housing recess, forming a cylindrical opening through which the power cord passes with a snug fit. In the second orientation, the cover plate is mounted on the housing upside-down relative to the first orientation, so that the cover plate recess faces away from the housing recess, and the cover plate protrusion fits snugly in the housing recess, so that no opening is formed. The housing preferably also includes a second, circular aperture through which a line lead can pass. This aperture is closed with a plug when not in use.
As is apparent from the above, it is an advantage of the invention to provide a new and improved electric motor housing. Other features and advantages of the invention will become apparent by consideration of the detailed description and accompanying drawings.